Children's Health: Better Protection From the Nasal Spray Flu Vaccine
Nasal spray or shot? When it's time for the annual flu vaccine, parents of small children may soon get to choose. The Centers for Disease Control and Prevention recommends flu shots for all children under 5, since they're at higher risk of developing flu-related complications, but the spray vaccine is currently approved only for older children. Now, a study published in the New England Journal of Medicine shows that the spray protects younger kids against the flu significantly better than the injection–with, of course, far less pain.
In the study, more than 7,800 children were randomly given either the spray vaccine, which contains a live form of the virus, or the injection, which contains an inactive virus. The spray group experienced 55 percent fewer cases of flu than the injection group. On the downside, toddlers under age 2 who got the spray were more likely to develop wheezing that required medical attention, with most cases occurring in babies under 1 year old.
"This was the first large trial of young children to definitively show the superiority of the live vaccine," says study leader Robert Belshe, a professor of infectious disease and immunology at the St. Louis University School of Medicine. It appears that the active virus in the spray triggers the body to mount a more complete immune response. That same protection, speculates Belshe, could lead to wheezing in some children since certain immune chemicals are known to interfere with lung function. For this reason, young children with a history of wheezing should not be given the vaccine, he says, nor should children under 12 months.
The Food and Drug Administration will still need to review the new data to deem whether the spray vaccine is safe for younger children or safe only for some. "We have to remember that we're administering this vaccine to healthy children, so there's an extra burden to provide the safest possible product," says Carolyn Buxton Bridges, the associate director for science and influenza policy at the CDC who cowrote an editorial that accompanied the study.
Another finding published this week in the online journal Public Library of Science Medicine indicates that the flu vaccine might offer some protection against the avian flu virus. Researchers from St. Jude Hospital injected mice with a modified form of the injectable vaccine and found that it protected about 50 percent of the mice from the avian virus after they were exposed to it. The researchers exposed the mice to high enough levels of the virus to ensure that all would have been infected had they not had the vaccine. "Our finding is certainly suggestive that flu vaccinations might provide some weak protection," says study leader and virologist Richard Webby. They may not stop people from getting avian flu, but they could protect people from becoming severely ill or dying from it."
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